This site is for people who like plants -- growers, enthusiasts, aesthetes, novices and professionals, those who appreciate wild things and those who appreciate the cultivated. I garden in Chelsea, and I've been visiting people's yards for 20+ years in the course of my work. My goal is to make this blog a community project, so if you share my interests, please consider becoming a participant and contributing content -- Guerin. Info: greenstreet@mindspring.com

Monday, July 30, 2012

An oddball pest on pine, an oddball condition on oak

I once grew a nice specimen of swiss stone pine (Pinus cembra). It's a five-needle white pine of European origin, and it grows at a much more modest rate than our native Eastern white pine. Given that my specimen was likely one in only a very small number in my end of Washtenaw County, it was disheartening when it was located by an odd caterpillar that wrapped itself in the needles and made a total mess of it. The insect was the pine webworm. (Or maybe it was a false pine webworm. I couldn't exactly figure it out.) I attempted monitoring so that I could spray when the insect was small. I tried this for a couple years. I never saw a small insect. One day the plant looked fine, the next day the new growth was destroyed by this annoying pest. After three years, the tree went into the compost. This year I saw the same damage on a five-needle Japanese white pine. I've never seen it on our native Pinus strobus.

Here's another oddball phenomenon, this one on oak. I won't call it a pest because it doesn't do damage of any consequence. It's called the vein pocket gall, and it is caused by a tiny maggot-like insect that feeds underneath the swollen tissue. There's an impressive number of insect species that create different types of deformities on oak leaves. The swelling can look like a hedgehog (the oak-hedgehog gall) or an apple (the oak-apple gall) or a potato (the oak . . you get the idea). Inconsequential to plant health. Fun to collect!

Saturday, July 21, 2012

A Lysimachia for all occasions

Lysimachia is genus of vigorous yellow-flowered plants, a fair number native to Michigan, and a small number common as garden specimens. They are called loosestrifes, but are unrelated to purple loosestrife (Lythrum salicaria).

I believe it is illegal to import seed or other plant materials of this genus. Like I said, they are vigorous. Moneywort (Lysimachia nummularia) is a case in point. The first time someone showed it to me, she said, 'uh-oh, bad ju-ju.' It's a low-growing creeping plant that ducks under the blades of lawn mowers; it also established itself in wet sites, riverbanks, and such. When I set up my first aquarium, I was surprised to see it listed as an aquarium plant in my little guide book. So I snatched a piece from the garden and voila! It's been very happy. 

Of the Michigan natives, the only one I've seen in cultivation is fringed loosestrife, L. ciliata. The one that is passed around has purplish leaves. I had it once. It seeded around too much. I eradicated it. This year I planted it again. We'll see. Since I have such dry soil, I don't fear it too much.

Gardening? Anybody gardening?

I don't know about you all, but when the temperature regularly exceeds 100 degrees, and it hasn't rained in a millennium, and the water-well breaks down, I stop with the gardening. About the only thing I've done in the last two or three weeks is triage on some of those woody plants whose leaves are turning yellow or crispy-dead. Amongst my perennials, the southern species of wild ginger Asarum arifolium, known colloquially as 'little brown jugs,' is my number one indicator species as it always tells me when things are getting critical. I can not explain why that particular species tugs at my heart so. That and Triosteum pinnatifidum, which is an asian counterpart to our native 'orange-fruited horse-gentian,' which certainly has the silliest name of anything that grows in Michigan, particularly since the plant has nothing to do with horses or gentians. Where was I? Oh, right, there's not much left of my asian h-g but I'm giving it water anyway. Fortunately I had broken off a piece earlier in the season and located it somewhere where the soil hadn't been ruined by earthworms.

So let's talk irrigation. What's the best way? Please chime in. I've tried hardware-store soaker hoses but they spring random leaks and squirt in random directions, and it's just about impossible to get the flat ones to make turns. This year I bought 1/4" plastic tubing from Loews, into which one can poke holes with a special hole-poker. You then insert an overpriced reducer into each hole so that it delivers a specified small number of gallons per hour. A section of 1/4" flexible vinyl tubing (which is available in various shades) can be attached to each reducer and extended to the plant that is to receive the drip. It's one tube per plant. Or you can link a stretch of vinyl tubing to a weeny elevated 'sprinkler' head and maybe reach a couple plants. That's my experience with it so far. It definitely does the job with great efficiency, but you can only buy the reducers in expensive little 4-packs. My next goal will be to find a better source where these things can be bought in good quantity. I'll start with A.M. Leonard (www.amleo.com), where you can buy components in packages of 100.

Here's a plant from my garden that doesn't mind the drought. It's a prickly-pear cactus (Opuntia) that I received from my neighbor Borek. I've never investigated its specific identity. The species that is native to Michigan and Ontario (O. humifusa) has long spines, as does the western species that is most commonly cultivated (O. polyacantha). The latter can be found in a lovely range of flower colors. Of course many other species of cacti can be grown in the open Michigan garden, but I've never delved in that area. If you grow any, please forward some pictures.

And, by the way, this picture was taken with my i-Phone with a lens attachment that allows for close-ups and fish-eyes. As was the following . . .

Yep, I took this picture with my iPhone. This is the viburnum leaf beetle (Pyrrhalta viburni) which I collected off a mangy beetle-eaten viburnum in Ontario last week. This is a new insect in our area. I found it in Ann Arbor for the first time two seasons ago. It definitely prefers arrowwood viburnum (Viburnum dentatum) over the popular fragrant species and hybrids.

Wednesday, July 4, 2012

Fourth of July allium fireworks

These are among my favorites. I love the summer alliums that open up like a display of fireworks. They are easy from seed. If they like the site, they will reproduce prolifically. First up is Allium flavum, from southern Europe. It is a plant that is readily available through seed exchanges, and numerous dwarf forms have been named. I admit I've had to toss out some ugly ones, but the common bright yellow one is quite nice.

Another very nice one is Allium carinatum subsp. pulchellum, also known as A. pulchellum and probably something else since I can't find it listed as either of those first names in my Random House Book of Bulbs by Roger Phillips and Martyn Rix (I highly recommend the entire series by these authors!).  I've read on more than one occasion that it can quite rambunctious, but that's never been my experience. I tried it up north at our cottage in the U.P. and it didn't survive more than one season amongst the northern white cedars and spruces. But even if it seeded around prolifically I'm not sure I would mind.

There are two common colors, white and lilac. The late garden author Jack Elliot strongly suggested deadheading them after flowering so that the colors didn't mix and turn into a dull mess. 

And then there is the nodding wild onion, Allium cernuum, which is native to North America from New York to British Columbia. Michigan flora says it is found on "marshy ground, swales and meadows, grassy forested banks, spreading along railroad embankments and roadsides." Flower color ranges from white to rose. All the photos in this post are from a garden within the Ann Arbor city limits. All are in flower now.

Ashes in southeast Michigan today -- little consensus

A green ash in Ann Arbor that sprouted from base
There are many young ash trees growing in woodlots and along fence rows in our area. There is also a small number of mature white ash trees that survived the original onslaught of the emerald ash borer. This spring I saw an enormous specimen off Maple Rd within city limits that was greater than three-feet in diameter with little taper in the first 30' of trunk. It had never been treated. More rarely one will stumble across a green ash that managed to maintain its original single stem.

This tree in Detroit retained its original trunk.
Ask a professional if there remains a local population of borers still threatening the remaining trees, and you'll get a range of answers. Kay Sicheneder at the City of Ann Arbor insists they are still out there in dangerous numbers. Mike McMahon at GreenStreet Tree Care agrees. I have some doubts. Maybe the insect is out there in small numbers like the bronze birch borer, searching for weakened and vulnerable specimens. Maybe the population will rise and fall like the elm leaf beetle in Ann Arbor or the calico scale in Plymouth.

What I don't see in my rounds is any recent damage from the borer. The trees that were never trimmed of deadwood can be returned to respectability by the judicious use of a chain saw. There may be a problem that the sprouts are weekly attached to the roots or parent trunk and will fail under load as they get heavier, but this we'll have to discover as the trees develop.

This is not to suggest that one should discontinue treatments of important landscape specimens. It's just not known what the future will bring.

Note original stem in the center of this green ash
As to that large white ash in Grosse Pointe (bottom photo), a couple years ago I did not see evidence that insecticides had been injected into its trunk. I don't believe any amount of Merit or the Bayer soil chemical would have been adequate to chase out the borers, so the tree must have had some innate resistance.  This year I could tell that it had been treated with 'Tree-Age' via trunk injection.



A modest white ash in Grosse Pointe

Strangeness amongst the Alliums

Two curious garden events just merged in my mind with a flash. Recently some four-foot tall allium stems appeared in my garden, and I've been waiting to see what kind of bizarre mutation will present itself. Also, I've long been wondering what ever happened to the pile of Allium 'Hair' bulbs I planted a couple years ago. Well, duh, I have just been informed by a friend that these are one and the same. She sent me a picture from her garden with the following note: "This mutation of the drumstick allium, A. sphaerocephalon, reaches 3 feet in my garden. It has threadlike tissue emanating from a burgundy center that looks like a cluster of beads.  Whether you like it or not, it is surely a conversation piece....." I'd say this is truly my kind of plant.